1. Field of invention
The field of the invention embraces air pollution abatement from fixed source locations that produce airborne contaminants.
Existing air pollution abatement uses several devices in various combinations for the treatment of a variety of raw stack gases. Stack gases may be produced from a combustion source, a chemical process, a mechanical process or any source that introduces contaminated aerosols, particulates or noxious gases into the atmosphere.
2. Examples of equipment presently in use
(1) Bag houses: Baglike devices made to fit over outlets from a pollution source. The bags trap larger particles and let the air pass through the interstices of the bags fabric. The bags may be removed and replaced when necessary.
(2) Mechanical filters: The filters are made in various densities, thicknesses and sizes, and are usually located in the duct/s exhausting the raw stack gases. The filters trap and impinge particles in the raw stack gases.
(3) Impingers: Impingers are similar to mechanical filters and have the same basic functions and results of mechanical filters.
(4) Cyclonal chambers: The chambers are cylindrical in shape and may be used as a saturator chamber and/or a particulate/dust removal system.
(5) Venturis: A device where the throat of a pipe is narrowed sufficiently to cause a decrease in pressure and an increase in the rate of flow of gas or air passing through the pipe. At the point where the pipe is narrowed, water may be introduced to scrub the gas. The throat of the pipe is usually of a variable and adjustable diameter.
(6) Electrostatics: A mechanical filter with an electromagnetic field that produces a stationary positive field that impinges tiny particles which are typically negatively charged.
(7) After burners: High temperature combustion to remove pollutants and gases by incineration.